CENTRAL TENDON OF THE DIAPHRAGM 109 



If you have been successful, the silver will have penetrated the 

 tendon and mapped out the lymph -channels, indicating an outline 

 of every lining cell by means of a dark border. Failure will result 

 only from non - attention to cleanliness in the handling of the tis^ 

 sue, in which case the silver becomes deposited generally over the 

 surface. The margins or outlines of the cells, it must be remem- 

 bered, are stained with the silver. The nuclei may be demon- 

 strated by after -staining with borax -carmine. The mounting 

 may be done in balsam, although the elastic fibers, of which the 

 matrix of the tendon is composed, will become stiff during immer- 

 sion, and show a tendency to curl and contract. If glycerin be 

 used after carmine staining, tissues should be washed thoroughly 

 in water, subsequently to the acid alcohol, transferred to equal 

 parts of glycerin and water,, and allowed to remain for an hour, 

 at least, before mounting. 



CENTRAL TENDON OF THE DIAPHRAGM. SILVER - STAINING 



(Vide Figs. 76 and 77) 



OBSERVE : 

 (L.) 



1. The division of the specimen into dark and light areas. 

 (The dark areas represent the more solid portions of the tissue or 

 the partitions between the channels, and the light spaces are the 

 lymph- paths.) 



2. The lymph-paths the light spaces. (These show, with 

 this amplification, as irregular, winding, and anastomosing courses, 

 marked with very delicate lace -like tracery the silver lines.) 



3. Valves of the lymph-paths. (At points, the paths will be 

 crossed by dark curved lines. These are imperfect valves, not 

 unlike a single cusp of an aortic valve.) 



(H.) 



4. Outlines of the cells lining the larger excavations 

 (lymph -paths) in the tissue.. (Note that the cells are generally 

 elongated in the direction of the lymph -path. The edges are 

 frequently serrated.) 



5. Stomata, minute openings at the junction of several cells. 



6. The construction of the valves. (These are curved against 

 the rymph-flow, and covered with cells like other parts of the 

 channel. Note the change in form of the cells approaching and 

 covering the valves.) 



